Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
328 views
in Technique[技术] by (71.8m points)

c# - Using LINQ to merge a list of objects

I have two lists of objects, using Linq I would like to merge them, but where the two lists contain objects with the same key, I only want the one with the greatest LastUpdated Value.

I thought that I could somehow get a list grouping by key a with max(LastUpdated) then join back to the list joining on key and LastUpdated, but there must be a more efficient way...

List<MyObject> lstListA = new List<MyObject>;
List<MyObject> lstListB = new List<MyObject>;

public class MyObject
{
    public string Key {get;set;}
    public string Value {get;set;}
    public DateTime LastUpdated {get;set;}
}
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

One option, using DistinctBy from MoreLINQ:

var query = lstListA.Concat(lstListB)
                    .OrderByDescending(x => x.LastUpdated)
                    .DistinctBy(x => x.Key);

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...